1. Field of the Invention
The present invention relates to the field of drum charging apparatus and, more particularly, apparatus for facilitating the transfer of materials within a drum or similar container into a reaction vat or other type of vessel.
2. Description of the Related Art
A number of industries involve operations which require the manual transfer of solid materials from transportable drums into processing equipment. Such activities are typically referred to as "the charging" of drums of materials into the process equipment. Such process equipment may comprise reaction vessels, tanks or other similar types of apparatus utilized to mix or otherwise process materials. These activities occur throughout commercial industry, but may be of particular concern in the pharmaceutical, chemical, cosmetic and food processing industries, where environmental and contaminant concerns are of a particularly high priority. For example, in the pharmaceutical and other chemical processing industries, potential hazards may exist with respect to chemical exposure and like dangers.
The drums which are utilized throughout these industries may be of a substantial weight. For example, in the pharmaceutical industry, drums comprising chemical materials may often weigh up to 80 kilograms. If employees attempt to manually manipulate such drums without the use of mechanical equipment to facilitate operations and otherwise provide mechanical assistance, such manual manipulation may often involve awkward "postures," thereby increasing risks of injury. Accordingly, drum charging clearly involves potential ergonomic hazards.
Another issue associated with drum charging systems, even those where substantial mechanical assistance may be provided, relates to the generation of air-transported particles in the form of dust and the like. Such dust may be readily generated within the work area when the materials are actually being transferred from the drum to the reaction vessel or similar container. Again, particularly within the pharmaceutical and other chemical industries, such dust may be highly toxic. Also, within any industry, the dust generated within the work area typically represents product loss. With expensive materials, the financial loss resulting from the dust generation may be significant.
Apparatus for facilitating the manipulation of drums during charging functions is known in the prior art. For example, the Habicht U.S. Pat. No. 5,205,699 issued Apr. 27, 1993 discloses a method and apparatus for lifting and tilting drums of flowable material. Referring specifically to the drawings and numerical references within the Habicht patent, a lifting and tilting apparatus 10 includes a base supported assembly 12, column assembly 14 and container support assembly 16. Contents of a receptacle 94 placed in the container support assembly 16 are dumped therefrom by vertical extension of the column assembly 14. The base support assembly 12 of the lifting and tilting apparatus 10 is relatively wide within respect to dimensions of the column assembly 14.
Habicht also generally discloses the concept of the use of a telescoping column attached to a base support. Interior of the column is a hydraulic cylinder to lift the sliding portion of the tubular column. As the sliding portion is lifted, the container support is lifted at twice the lift rate of the column. The container support is independently tilted at any convenient height between the lifting extent of the apparatus. The tilting of the container support is provided by an air-operated gear motor and carried on a moveable carriage. The moveable carriage and gear motor are fully contained interior of the telescoping column. A slot is provided in the column so as to allow the independent lifting and tilting of the container support by an operator.
In general, Habicht discloses a system comprising a lifting and tilting apparatus capable of being tilted independently of the lift. The system is considered useful with equipment having non-uniform receiving heights for their apertures, mouths, openings and the like which accept the material discharge from the receptacle. Accordingly, the Habicht patent is described as providing an apparatus capable of being utilized with a variety of processing equipment.
Another system is disclosed in the Haynes U.S. Pat. No. 5,558,485 issued Sep. 24, 1996. The Haynes patent discloses a lifting and dumping apparatus 10 in which a container 12 is lifted and dumped. The container 12 is pivotally attached to the lift and dump apparatus 10 by means of pivot pins 52. A hydraulic cylinder 56 tips the container 12, and dumps the contents therein when the hydraulic cylinder 56 is extended. The lift and dump apparatus 10 is stabilized by a pair of rearwardly extending base legs 40. In particular, the Haynes arrangement is described as providing an apparatus which can be manually maneuvered into position adjacent a conveyor belt, so that a worker can unload articles therefrom hydraulically onto the conveyor belt.
The Elliott U.S. Pat. No. 731,442 is an extremely early disclosure of a sack holder having a pivotable holder H. The holder H is normally disposed in a vertical orientation, but can be lifted and pivoted by grasping at handle z. The lifting and pivoting of holder H allows the contents of a sack resting therein to be emptied into a hopper c. The lift is manually powered and includes a base having feet m radiating so as to form a relatively broad base of support.
Another disclosure of a lifting and tilting mechanism is shown in the Wheat U.S. Pat. No. 3,057,498. The Wheat patent discloses a trash holder having a receptacle 50 automatically lifted and tilted to dump the contents therefrom. The receptacle 50 includes a closure member or lid 70 pivotally attached to the receptacle 50 at a hinge connection 72. Upon lifting and tilting the receptacle 50, gravity is utilized so as to rotate the closure member 70 downward, thereby opening the receptacle 50 and allowing the contents to be emptied. As the contents of the receptacle 50 are emptied, the closure member 70 apparently forces the contents to travel along the length of the member 70 before undertaking a "free fall" into a receiving structure.
Issues associated with dust removal have also been addressed in the prior art. For example, the Schulte U.S. Pat. No. 3,985,245 discloses an arrangement for charging the coal bins of hopper cars. The arrangement includes a weighing bunker 1 which extends in a downward direction as a tubular discharge connecting piece 2. The tubular discharge connecting piece 2 comprises a suction port 20 which removes dust generated by the dumping of the coal. The suction port 20 is connected to a tubular wall which forms an annular chamber for collection and removal of coal dust.
Correspondingly, the Borgner U.S. Pat. No. 4,627,781 discloses a bag cutting and emptying device 1 having a connected, collective dust removal filter. The device 1 includes a bag chute 8 connected to a transfer funnel 30, into which the contents of the bag are dumped. The bag chute 8 is provided with a pivotable flap 8.1, through which empty bags can be delivered to an empty bag compacting device 26. The device 1 includes a suction filter 32 disposed on its top, which serves to prevent dust from escaping into the working environment.
Another device is disclosed in the Mori U.S. Pat. No. 3,405,820. The Mori device comprises a hopper which is constructed with an absorption element 12 utilized to create an air curtain 9. The air curtain 9 serves to prevent dust from escaping into the outside environment. The air curtain 9 apparently comprises a flow of air in a single, linear direction.
A further device is disclosed in the Wendler U.S. Pat. No. 5,275,662. The Wendler, et al. patent discloses a flooring material applicator device 10 having a mixing chamber 20, which mixes material dumped therein from first and second component hoppers 22, 24, respectively. The first component hopper 22 is lifted and tilted by a hydraulic cylinder 76. The lifting action of the hydraulic cylinder 76 rotates the first component hopper 22 about an axis defined by hinges 74. A hydraulic cylinder 72 lifts the rear end of the second component hopper 24, so as to dump the contents therein into the chamber 20.
Another device is disclosed in the Riemersma U.S. Pat. No. 5,302,073. The Riemersma, et al. device comprises a lift and seal drum dumper for dumping the contents of a drum. Dumper 10 includes a hollow hood assembly 36 which fits over and above a drum D. The hollow hood assembly 36 includes a small diameter end 49, through which the contents of the drum D eventually exit. The drum D is tilted by means of a hydraulic cylinder 23.
Although prior art exists with respect to drum charging systems, the known prior art still does not address several significant problems. For example, production buildings in industries such as the pharmaceutical and chemical industries often have processing vessels located in relatively congested areas with limited head space. This head space is often limited because of low ceilings, significant and complex piping or other processing equipment. Drum dumping systems which are known and commercially available for use in such buildings are relatively large, heavy and difficult to maneuver within the limited space. In fact, these systems often counteract the weight of the drum with the weight of the drum manipulator. Also, known systems which may be utilized within various industries are often significantly expensive.
Other problems also exist with respect to known systems. For example, several drum dumping systems are often limited to serving only one vessel, and are therefore permanently installed within the industrial establishment. If the systems are installed in a manner such that they are permanently attached to the floor, such systems may take up valuable space when not needed, and are often relatively "bulky." Other systems may be attached overhead, such as to a rail system or the like. As earlier mentioned, and particularly in industries such as the pharmaceutical and chemical industries, overhead space may be required for relatively complex piping systems. Also, such overhead systems are also often limited to serving only one vessel. With respect to dust removal and similar types of ventilation systems, the inventors believe that the prior art is relatively limited. For example, the use of ventilation sleeves appears to comprise sleeves which ventilate only part of an opening. Also, the inventors understand that such sleeves may not have disposal ports for bags comprising toxic or other contaminant materials.
In view of all of the foregoing, there is a need for a drum charging system which is relatively economical, light-weight, portable, small and capable of serving multiple vessels. Also, it would be advantageous for such a system to be relatively low with regard to labor intensity, requiring a minimal number of operators while still charging drums relatively quickly. Finally, it would also be advantageous for such a system to operate in conjunction with a dust containment system.